Re: [PATCH v5 2/7] drm/panel: simple: Add ability to override typical timing

From: Doug Anderson
Date: Mon Jul 01 2019 - 12:39:24 EST


Hi,

On Sun, Jun 30, 2019 at 1:55 PM Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
>
> Hi Douglas.
>
> > > +
> > > + /* Only add timings if override was not there or failed to validate */
> > > + if (num == 0 && panel->desc->num_timings)
> > > + num = panel_simple_get_timings_modes(panel);
> > > +
> > > + /*
> > > + * Only add fixed modes if timings/override added no mode.
> >
> > This part I fail to understand.
> > If we have a panel where we in panel-simple have specified the timings,
> > and done so using display_timing so with proper {min, typ, max} then it
> > should be perfectly legal to specify a more precise variant in the DT
> > file.
> > Or what did I miss here?
>
> Got it now.
> If display_mode is used for timings this is what you call "fixed mode".
> Hmm, if I got confused someone else may also be confused by this naming.

The name "fixed mode" comes from the old code, though I guess in the
old code it used to refer to a mode that came from either the
display_timing or the display_mode.

How about if I call it "panel_simple_get_from_fixed_display_mode"?
...or if you have another suggestion feel free to chime in.

NOTE: Since this feedback is minor and this patch has been outstanding
for a while (and is blocking other work), I am assuming that the best
path forward is for Heiko to land this patch with Thierry's Ack and
I'll send a follow-up. Please yell if you disagree. I'll respond to
each of your emails separately and then wait for your response before
sending the follow-up series.


-Doug